1-(alicyclic substituted carbonyl)-3-indolyl aliphatic acid derivatives



United States Patent Office 3,541,112 l-(ALICYCLIC SUBSTITUTED CARBONYL)-3- INDOLYL ALIPHATIC ACID DERIVATIVES Hisao Yamamoto, Nishinomiya-shi, Yasushi Nakamura, Hirakata-shi, Toshio Atsumi, Takarazuka-shi, Masaru Nakao, Osaka, Tsuyoshi Kobayashi, Minoo-shi, and Chiharu Saito and Hiroshi Awata, Toyonaka-shi, Japan, assignors to Sumitomo Chemical Company, Ltd., Osaka, Japan, a corporation of Japan No Drawing. Filed July 7, 1967, Ser. No. 651,705 Claims priority, application Japan, July 13, 1966, 41/ 46,141 Int. Cl. C07d 27/56 US. Cl. 260-32613 9 Claims ABSTRACT OF THE DISCLOSURE A new l-acyl-S-indolyl aliphatic acid derivative having anti-inflammatory and anti-cholesterolemic effects which is characterized in that the l-acyl-substituent is an alicyclic-substituted carbonyl or an alicyclic-substituted alkylcarbonyl group, and processes for producing such compound.

The present invention relates to novel N-substituted indole derivatives having high anti-inflammatory, antipyretic, analgesic and anti-cholesterolemic activities and to processes for producing the same. More particularly, the present invention relates to novel l-(alicyclic group substituted carbonyl)-3-indolyl aliphatic acid derivatives or l-(alicyclic group substituted alkyl-carbonyl)-3-indolyl aliphatic acid derivatives and processes for producing the same.

Of the developed non-steroidal anti-inflammatory compounds, 1-(p-chlorobenzoyl)-2-methyl-5-methoxy 3 indolylacetic acid is the greater anti-inflammatory activity, but it is remarkably high in acute and chronic toxicities. The present inventors observed that even when 10 mg./ kg. of said compound was orally administrated to animals, occult bleeding was observed in feces. In addition thereto, all the conventional anti-inflammatory compounds tend to promote the bleeding of digestive organs and not few examples have been reported that perfolations of the stomach and intestines brought one to death. Further, 1,2-diphenyl 3,5 dioxo-4-n-butylpyrazolidine (phenyl butazone), which is most widely used as antiphlogistic now-a-day, has low activity in comparison with its high acute toxicity and hence is considerably small in therapeutic ratio.

The syntheses of indole derivatives having acyl groups at the N-positions are described in, for example, Elderfield: Heterocyclic Compounds, vol. 3 (1952), chapter 1, pages 1-247, and W. C. Sumpter and F. M. Miller: Heterocyclic Compounds with Indole and Carbazole Systems (1954), pages 1-69. l-substituted acyl groups of l-acyl-indole derivatives are so easily hydrolyzed by acid or alkali that it has been considered impossible to obtain l-acyl-indole derivatives directly from corresponding N -acylated phenylhydrazine derivatives by Fischers indolization. Suvorov et al. [Suvorov et a1.: Doklady Acad. Nauk U.S.S.R.,' 136, 840 (1961), Chem. Abstr.,

3,541,112 Patented Nov. 17, 1970 55, 17621 (1961), J. Gen. Chem., U.S.S.R., 28, 1058 (1958)] have recently reported this problem as follows:

The present inventors prepared many 1-acyl-3-indolyl aliphatic acid derivatives and tested various kinds of pharmacological effects thereof. As a result, the present inventors found novel 1-acy1-3-indolyl aliphatic acid derivatives having high anti-inflammatory, anti-pyretic, analgesic and anti-cholesterolemic activities.

One object of the present invention is to provide novel 1-acy1-3-indolyl aliphatic acid derivatives having hi h anti- 7 gig/ I wherein R is a non-substituted, or a halogen-, alkylor phenyl-substituted or benzene ring-condensed, saturated or unsaturated monoor poly-alicyclic group, or an alkyl group substituted by said alicyclic group; R and R are, individually a hydrogen atom or lower alkyl group; R is a hydrogen atom or alkoxycarbonyl group; R is a hydroxy, alkoxy, benzyloxy, tetrahydropyranyloxy or amino group; R is an alkyl, alkoxy or alkylthio group or a halogen or hydrogen atom; p is 0 or 1; and n is 0 or an integer of 1 to 3.

Further, the present invention provides a process for producing novel 1-acyl-3-indolyl aliphatic acid derivatives represented by the Formula I, which comprises reacting an N -acylated phenylhydrazine derivative of the formula:

wherein R and R have the same meanings as identified above, or a salt thereof with a ketone compound of the formula:

wherein R R R R 11 and 12 have the same meanings as identified above, to yield the 1-acyl-3-indolyl aliphatic acid derivative (I).

Still further, the present invention provides a process for producing novel 1-acyl-3-indolyl aliphatic acid derivatives represented by the Formula I, which comprises decomposing an N -acylated phenylhydrazone derivative of the formula:

Ru CO wherein R and R have the same meanings as identified above, and B is a ketone or aldehyde residue, with an acid to yield an N -acylated phenylhydrazine derivative of the formula:

R (II) n 11 (V) wherein R and B have the same meanings as identified above, with a compound having the formula:

I c o It (VI) wherein R has the same meanings as identified above and Y represents a halogen or an ester residue, to yield an N -acylated phenylhydrazone derivative represented by the Formula IV, decomposing the resultant N -acylated phenylhydrazone derivative with an acid to yield an N -acylated phenylhydrazine derivative represented by the Formula II, and reacting the resultant N -acylated phenylhydrazine derivative represented by the Formula II with a keto-aliphatic acid derivative represented by the Formula III to yield the 1-acyl-3-indolyl aliphatic acid derivative (I).

Still further, the present invention provides a process for producing novel 1-acyl-3-indolyl aliphatic acid derivatives of the Formula I, which comprises reacting a phenylhydrazine derivative of the formula:

R v11 wherein R has the same meaning as identified above, with a compound having the Formula VI to yield an N acylated phenylhydrazine derivative of the Formula II and reacting the resultant N -acylated phenylhydrazine derivative (II) with an aliphatic acid derivative of the Formula III to yield an 1-acyl-3-indolyl aliphatic acid derivative (I).

Still further, the present invention provides a process for producing novel 1-acyl-3-indolyl aliphatic acid derivatives of the formula:

1& (Vlll) wherein R R R and R have the same meanings as identified above, which comprises reacting an N -acylated phenylhydrazine derivative of the Formula II with a compound of the formula:

wherein R and R have the same meanings as identified above, to yield an 1-acyl-3-ind0lyl aliphatic acid derivative (VIII).

Still further, the present invention provides a process for producing novel 1-acyl-3-indolyl aliphatic acid derivatives represented by the formula:

wherein R R R R and n have the same meanings as identified in the Formula I, which comprises converting a compound represented by the formula:

I'l (XII) wherein R R R R and n have the same meanings as identified above; and R represents an alkoxy, tetrahydropyranyloxy, benzyloxy or amino, to a 1-acyl-3- indolyl aliphatic acid derivative (XI).

Still further, the present invention provides a process for preparing 3-indolyl aliphatic acid derivatives represented by the Formula I which comprises reacting at an elevated temperature, in the absence or presence of an organic solvent and a suitable condensing agent, a hydrazone derivative represented by the general formula:

R (IV) wherein R R R R 11 and p are the same as in the case of the Formula I.

Furthermore the present invention provides a pharmaceutical composition containing an effective amount of the 3-indo1yl aliphatic acid derivative of the Formula I, as the essential active ingredient, and a pharmaceutically acceptable carrier.

According to the present invention, 1-acyl-3-indolyl' aliphatic acid derivatives represented by the Formula I are prepared by the reaction shown by the following equations:

R1-OO-Y Ru Ru CO IV R (VII) (III) or ,r/u w oo R3 R4 hH c1-r2)..(drr),ooa

Rfl R2 I In the above formulae,-R R R R R R B, Y, n and p have the same meanings as identified above.

In the processes of the present invention, N -acylated phenylhydrazine derivatives (II) and N -acylated phenylhydrazine derivatives (IV) can be. synthesized by other processes than those discolsed herein. These intermediates, the compounds (II) and (IV), are novel compounds.

Next, the process of the present invention is explained in due order as follows.

I Firstly, the reaction of a phenylhydrazone derivative (V) and a compound (VI) will be described.

The reaction of a phenylhydrazone derivative (V) with a compound (V1) is carried out in a basic solvent or in an inert solvent in the presence of a hydrogen halide acceptor. As the hydrogen halide acceptor, a tertiary amine, for example, pyridine or dirnethylaniline can be used. These hydrogen halide acceptors themselves can be used as solvents. Inert solvents such as ether, benzene, toluene, and tetrahydrofuran are also able to be used as reaction solvents. At least an equimolar or larger amount of a hydrogen halide acceptor is required to accept the hydrogen halide which is produced in course of the reaction and to make the reaction progresses smoothly. The compound (VI) may be chloride, bromide, iodide or fluoride, and chloride is most preferable from commercial point of view. The reaction proceeds at a room temperature, and even below 0 C., and the yield is high. The exothermic reaction finishes in a few minutes or several hours. After the reaction finishes, the produced hydrogen halide salt of the hydrogen halide acceptor is filtered off and the filtrate is concentrated under reduced pressure, or the reaction mixture is poured into water or a solvent inwhich the aimed. N -acylated phenylhydrazone is not "dissolved, and the aimed N -acylated phenylhydrazone compound of the said Formula IV is easily obtained as crystals or an oily substance. These products can be purified by an appropriate solvent, for example, a solvent mixture of alcohol and Water.

Examples of the N -acylated phenylhydrazone compounds obtained by the method of the present invention include following compounds. I

Acetaldehyde N -(Z-hydrindenylformyl)-N -(p-methoxyphenyl) hydrazone Acetaldehyde N -(2-hydrindenylformyl)-N- -(p-methy1- thiophenyl) hydrazone Acetaldehyde N -(2-hydrindenylformyl) -N -(p-methylphenyl) hydrazone Acetaldehyde N (A -tetrahydrobenzoyl -N (p-methylphenyl hydrazone Acetaldehyde N -(A -tetrahydrobenzoy1)-N -(p-chlorophenyl) hydrazone Acetaldehyde N -(A -tetrahydrobenzoyl)-N -(p-methy1- thiophenyl) hydrazone Acetaldehyde N -(a-cyclohexylpropionyl) -N -(p-methoxyphenyl hydrazone Acetaldehyde N (4-phenyl-A -tetrahydrobenzoyl) -N (p-methoxyphenyl) hydrazone Acetaldehyde N 1,2,3,4-tetrahydro-2-naphthoyl) -N (p-methoxyphenyl)hydrazone Acetaldehyde N -(cyclohexylformyl) -N (p-methoxyphenyl) hydrazone Acetaldehyde N (4-methyl-cyclohexylformyl) -N (m-methoxyphenyl) hydrazone Acetaldehyd N (cyclohexylformyl) -N (m-methylphenyl) hydrazone Acetaldehyde N 1-methy1-2-hydrindenylformyl)-N (p-methoxyphenyl) hydrazone Benzaldehyde N Z-hydrindenylformyl) -N (p-methoxyphenyl hydrazone Chloral N (2-hydrindenylformyl) -N (p-methoxyphenyl) hydrazone Methylethylketone N -(Z-hydrindenylformyl) -N (p-methoxyphenyl) hydrazone v Acetphenone N (2-hydrindenylformyl) -N (p-methoxyphenyl) hydrazone In addition thereto, there are obtained compounds having as R the following substituents:

on,- 1-(3-indeuyl)-ethyli 1 Z-methyl-l eyelohexenylmethyl- 3-iucth yl-l-cycloliexeuylincthyl- 3-1110llrylcyclopuutyl- 2-niothylcyclopcutyl- 2-1nethylcyclopropyll-methyI-Z-hydrindenyll-iuctl1yl-3-iudcuyl- 2-hydriudenyl- 1,2,3,4-tctral1ydro-l-nuphthyl- A -tctrahydro-m-tolyl- A tctiuhydr-m-t0ly1- A -tctrahydro-iu-tolyl- A -tctral1ydro-p-tolyl- Cyclopuntyl- A -cyclopentenyl- -cycl0penteuyl- CHg Cyclopropyl- Nfl-cyclohoxadicuyl- A -dihytlru-l-nuphtllyl- A -tllll)tll'O-l-lltlfilltilyl' A -dihydro-2-naphtl1yl- A dihydro-2naphthyl- A -dihydro-2-uaphtl1yll-phcnyl-1-cycl0pentyl- Those novel N -acylated phenylhydrazone derivatives, which are obtained by the method of the present invention, have psychic, stimulating, anti-tumor, bactericidal, and fungicidal activities and they are very important compounds as intermediates for producing remarkably effective anti-inflammatory and anti-cholesterolemic drugs, analgesics and anti-pyretics.

Next, the process for producing an N -acylated phenylhydrazine derivative (II) by decomposing an N -acylated phenylhydrazone derivative (IV) will be described.

An N -acylated phenylhydrazone derivative (IV) is dissolved or suspended in an adequate solvent, for example, methanol, ethanol, benzene or toluene. Thereto is added more than equivalent amount of an acid. As an acid, an inorganic acid or an organic acid can be used, among which an inorganic acid such as gaseous hydrogen chloride is preferable to give a good result. If hydrochloric acid is used, :1 H01 salt of the N -acylated phenylhydrazine derivative (II) precipitates as crystals in good yield. Sulfuric acid or others can be used in place of gaseous hydrogen chloride. When ether, benzene or toluene is used as the solvent, a small quantity of alcohol should be added to it.

The reaction temperature is preferably 0-2S C., though it may be below 0 C.

As the N -acylated phenylhydrazone derivative (IV), various compounds can be illustrated. For example, the hydrazones of acetaldehyde, chloral, benzaldehyde, acetal, ethyl acetoacetate and methoxy acetone can be easily decomposed in general cases to give the aimed N -acylated phenylhydrazine derivative (II). Among them, the hydrazone of acetaldehyde has especially distinctively commercial advantages.

3,541,112 9 Examples of the N -acylated phenylhydrazine derivapound or N ,N -diacylated compound. The reactions are tives (II) obtained by the method of the present invenshown, for example, as follows: tion, include:

N -(2-hydrindenylformyl -N (p-methoxyphenyl) hydrazine 5 V N (A -tetrahydrob enzoyl) N (m-methoxyphenyl) hydrazine o H; NH-NH2 (Jr-i o N -(A -tetrahydrobenzoyl) -N (m-methoxyphenyl) (021mm hydrazine 1; 1

N -(2-hydrindenylformyl)-N -(p-methoxyphenyl) CHZO NH NH C O hydrazine N (Z-hydrindencylformyl) -N (p-methylphenyl) C 0 hydrazine N -(Z-hydrindencylformyl)-N -(p-methy1pheny1) 1 5 hydrazine N -(2-hydrindenylformy1) -N -(p-chloropheny1) hydrazine N -(2-hydrindenylformyl)-N -(p-methylthiophenyl) hydrazine N (4-phenyl-A -tetrahydrobenzoyl) -N (p-methoxyphenyl hydrazine N -(a-cyclohexylpropionoyl)-N -(p-methoxypheny1) m hydrazine N 1,2,3,4tetrahydro-2-naphthoyl) -N (p-methoxy- 1: 2

phenyl)hydrazine a N (4-methyl-A -tetrahydrob enzoyl) -N (p-methoxy- 0 phenyl) hydrazine N -(cyclohexylformyl)-N -(p-methoXypheny1) $0 hydrazine Their salts, for example, hydrochlorides, sulphates and phosphates, can be easily obtained. All of them are novel compounds that have not been reported in any literature. Th bj i NLacylated d i i (11) i il Sepa- These compou ds ha p yc Stimulating, anti-tumor, rated from the by-products by their solubility dilferences bactericidal and fungicidal activities and further they i an organic Solvent H h ifi i f h are very important as intermediates for producing strong N -acylated compound is not necessary in the process, anti-inflammatory and anti-cholesterolemic drugs, analbecause only the N -acylated derivative is concerned with gesics and anti-pyretics. the following reaction in the present invention.

In some cases a novel N -acylated phenylhydrazine According to the process of the present invention, derivative (II) is directly obtained by reacting a phenylfor example, the compounds having the following subhydrazine derivative (VII), stituents, which are represented by R and R in the said Formula II are obtained.

4 R 1,2,3,4-tet1'ahydr0-1-naphthyl- NHNH2 (VII) OH; '50 r .wherein R has the same meaning as identified in the Formula I, or a salt thereof, with a compound (VI) 1 R COY (VI) wherein R has the same meanings as identified inthe 7 said Formula I and Y is a halogen atom in this case, A -tetmh dro-m-tol tin the presence of a basic agent.

i This reaction is carried out in a conventional solvent such as benzene, toluene, Xylene, ether, dioxane or tetrahydrofuran in the presence of a hydrogen halide ac- CH ceptor such as a tertiary amine. As the tertiary amine, triethyl amine, pyridine or dimethylaniline is suitable A -tetrahydro-m-tolyland equimolar or larger amount of the acceptor than that of the said phenyl'hydrazine derivative (VII) is required.

This reaction proceeds so rapidly that the compound I 011 (VI) is added slowly to a phenylhydrazine derivative (VII) in a suitable solvent under cooling. The reaction A -tetrahydro-p'tolyb mixture is stirred at room temperature, and if necessary heated to complete the reaction. As a compound of the Formula VI, acid chloride, acid bromide, etc. can be used.

The N -acylated derivative (II) thus obtained is concyclopentyl. I taminated with a by-product such as N -acylated com- A -cyclopentenyl- A'-'-cyclopentenyl- Cyclopropyl- A -cyclohexudlouyl- A -dihydro-l-naplithyl- N-dihydro-l-naphthyb.

AMihydro-Z-naphthyl- A -dihydro-Z-naphthyl- A -dil1ydr0-2-naphthyl l-phouyl-l-cyclopcutyl Z-lndenyll-indenyl- S-indonylmethyl- 1-(2-ldnenyl)-othyl- 1-(3'-indenyl)etl1yl- 2-mathyl-l-cyclohexenylmethyl- 3-methyl-l-cyclohoxenylmethyl- 3-methylcyclopentyl 2-mothylcyclopeutyl- 2-hydrindenyl- 1 R hydrogen, m-chloro-, p-chloro-, m-bromo-, p-methyl-, p-ethyl-, m-ethyl-, m-methoxy-, pmethoxy-, p-ethoxy-, p-methylthio-, p-ethylthio-.

Next the process for producing a l-acyl-3-indolyl aliphatic acid derivative (I) by the reaction of an N acylated phenylhydrazine derivative (II) with an aliphatic acid derivative (III) will be described.

This reaction is carried out by heating in the presence or absence of an adequate condensing agent, in an organic solvent or absence of solvent. The yield is very high.

The present reaction proceeds smoothly even without a solvent, but the reaction is more smoothly carried out in a solvent. An organic acid, for example, acetic acid, formic acid, propionic acid, lactic acid, butyric acid, a non-polar organic solvent, for example, n-hexane, benzene or toluene, and other organic solvent, such as dioxane and dimethyl formamide, can be used as a solvent of this reaction. When an alcohol is used as a solvent in this reaction, a corresponding ester of indole aliphatic acid is produced in some cases.

A S-Substituted indole derivative can be prepared in ring formation reaction of an N -para-substituted phenylhydrazine derivative, however in case an N -meta-substituted phenylhydrazine derivative is used, two isomers, 4- and 6-substituted indole derivatives can be obtained as follows: For example,

CH30 CHZC OH [CH3 N These isomers can be generally separated by column chromatography. c

The reaction proceeds smoothly at a temperature within the range of 60 to 140 C. The reaction proceeds rapidly and generally finishes in a short period of time, mostly in one or two hours. The condensing agent is not needed in some cases but desirable results are generally achieved by using a condensing agent. The condensing agent includes inorganic acid such as hydrochloric acid, sulfuric acid and phosphoric acid, metal halides such as zinc chloride and copper chloride, heavy metal powder such as copper powder, boron fluorides or polyphosphoric acid.

In after-treatment, the reaction mixture is allowed to stand at room temperature or in a refrigerator (about 5 C.), then a large amount of crystals of the product is mostly obtained. I

When crystals do not produce, the reaction mixture is concentrated under a reduced pressure, or water, acetic acid-water or petroleum ether is adequately added to the mixture, then, beautiful crystals can be obtained. The produced crystals are collected by filtration and they are generally washed with an aqueous solution of acetic acid, alcohol-water, water or petroleum ether before they are dried. Ether, acetone, acetone-water, alcohol, alcoholwater, benzene and acetic acid are generally preferred as a solvent for recrystallization of the present compound. The crystal system varies with a kind of a recrystalliza tion solvent. Objective products are generally crystalline, but oily products are sometimes given in the ester compounds.

Reaction solvents, reaction conditions, condensing agents and recrystallization solvents which have been mentioned above are, only presented as illustrative of the present invention but not in its limitation, needless to speak of.

i 14 The compounds having following substituents, for example, are easily obtained in good yield, theoretically or in nearly theoretically, according to the process of the present invention.

1- A '-tetr ahydrobenzoyl) -2-methyl-5-meth0xy-3 indolylacetic acid 1- (A '-tetrahydrobenzoyl) -2-methyl-5-chloro-3 indolylacetic acid 1-(A '-tetrahydrobenzoyl)5-emethoxy-3-indolylacetic acid 1-(A '-tetrahydrobenzoyl) -2,5-dimethyl-3 -indolylacetic acid 1-(A -tetrahydrobenzoyl)-2-methyl-3-indolylacetic acid l-(A -tetrahydrobenzoyl)-2-methyl-5-methylthio-3- indolylacetic acid 1- (A -tetrahydrobenzoyl) -2-methyl-5-ethoxy-3- indolylacetic acid Dimethyl l-(A '-tetrahydrobenzoyl) -2-methyl-5- methoxy-3-indolylma1onate 1- (A '-tetrahydrob enzoyl) -2-methyl-5-methoxy-3 indolylacetic acid amide Tertiary butyl 1-(A '-tetrahydrobenzoy1)-2-methyl-5- methoxy-3-indolylacetate Ethyl 1-(A '-tetrahydrobenzoy1)-2-methy1-5-methoxy- 3-indolylacetate Methyl 1-(A '-tetrahydrobenzoy1)-2-methyl-5-rnethoxy- 3-indolylacetate Tetrahydropyranyl 1- A '-tetrahydrobenzoyl) -2-methy1- 5-methoxy-3 -indoly1acetate CHsOQIGHzCOO O 'y-[ 1- (A '-tetrahydrobenzoyl) -2-methyl-5-methoxy-3- indolyl] -butyric acid CHaO CHzCHnO H20 0 OH a-[ 1- (A '-tetrahydrobenzoyl) -2-metliyl-S-methoxy-3- indolyl] -propionic acid 1- (A '-tetrahydro-4'-phenylbenzoyl) -2-methyl-5-methoxy- 3-indoly1acetic acid I 1-(A '-tetrahydrobenzoyl)-2-inethyl-4-methoXy-3- indolylacetic acid and 1-(A '-tetrahydrobenzoy1)-2- methyl-6-methoxy 3-indolylacetic acid 1-(A '-tetrahydrobenzoyl)-2,4dimethyl-3-indolylacetic acidand. 1- (A -tetrahydrobenzoyl -2,6-dimethyl-3- indolylacetic acid 1-(A '-tetrahydrobenzoyl)-4-methyl-3-indolylacetic acid and l 1-(A '-tetrahydrobenzoyl)-6-methy1-3-indolylacetic acid methoxy-S-indolylacetic acid l 1-(A -tetrahydro-4 methylbenzoyl)-2-mcthy1-5- methoxy-B-indolylacetic acid CHsO CHZCOOII 5 \N [CH1 I OH;

1-tr1cyclen0yl-2-methyl-S-methoxy-B-mdolyacehc acld CH3O OHzCOOH +0 0 0 011 I CH I 41ml CHz-CH- H2 1-(cyclohexylchloroacetyl)-2-methyl-5-methoxy-3- indolylacetic acid CHaO 011200011 [CH f CO (:JHCI

1-(m-cyclohexylpropi0noyl)-2-methyl-5-methoxy-3- indolylacetic acid CH3 CHzCOOH \N [CH3 O CH-CHa 'y-[ 1- a-cyclohexylpropionoyl-2,5 -dimethy1-3-indolyl] butyric acid. a-[ 1- a'-cyclohexylpropionoyl -5-chlor0-3 -indolyl] propionic acid. 1-(a cyclohexylpropionoyl)-4-methylthio-3-indolylacetic acid and 1-(dwyclohexylpropionoyl)-6-methylthio-3-indolylacetic acid. In addition to these, there are easily obtained compounds having as R the following substituents:

X -tctraliyd1'0-m-t0lyl- A -tctrahydro-in-tolyl- A -tuLi'ahydro-m tolyb.

A -tetraliydro-p-tolyl- Cyclopontyl- A -cyclopontcnyl- A cyclopentcnyl- Oyclopropyl N-dihydro-l-naphthyl- A -dillydro-l-nuphthyl-.

A -dihydroQ-naphthyl- A -dihydi'o-2-naphtl1yll-plienyl-l-cyclopcntyl- 2-indcuyl- V.

l-indenyl- 3-indenylrnethyl- 1-(2-indenyl)-ethyl- 1-(3 -indenyl)-ethy1- CH3 A CH? 2-rnethyl-l-cyclohexenylmethyl- 3-methyl-l-cyclohexenylmethyl- 3-methylcyclopentyl- 2-methylcyclopentylm 30 CH 2methy1cyclopropyll-methyl-Zhydrindenylr L 1-methyl-3-indenyl- \J i 2-hydrindeny1- l L Many other 1-acyl-3-indolyl aliphatic acid derivatives can be thus synthesized. i

Further in some cases a l-acyl-3-indolylacetic acid derivative of the formula,

I C H C O O H 6 5 R 7 (I) O R wherein R R R and R have the same meanings as identified in the Formula I, is prepared from an N -acyl phenylhydrazine derivative (II) or salt thereof and a keto-dicarboxylic acid of the Formula IX or X.

In this reaction, a phenylhydrazine derivative of the Formula II is heated with a keto-dicarboxylic acid of the Formula ]X or X in the presence or absence of a condensign agent in an organic solvent or absence of organic solvent. The reaction temperature is within the range of 45 to 200 0., preferably 60 to C. As an organic solvent, organic acids such as formic acid, acetic acid, propionic acid and butyric acid, a hydrocarbon such as benzene, toluene, xylene, cyclohexane and n-hexane, dioxane, isopropyl ether, acetonitrile, butanol, ethyleneglycolether and the others can be used.

As a condensing agent, inorganic acids such as hydrochloric acid and sulfuric acid, metal halides such as zinc chloride and copper chloride, boron fluoride, polyphosphoric acid and the others can be used.

This process does not require a complicated manner or operation and the yield is remarkably high.

For example, this process is shown as follows:

OHQO

O O OH 1TINH2 CHaC 0 0112011 0 0 o 0 OH HCl 01-130 CHzCOOH \N H-CH: t" l C 0 Still further, according to the present invention a l-acyl- 3-indolyl aliphatic acid derivative (XI) is obtained by converting an ester or amide derivative (XII) of a corresponding 3-indolyl aliphatic acid (XI).

For example, a benzyl ester of a 3-ind0lyl aliphatic acid is converted to a free 3-indolyl aliphatic acid derivative by hydrogenating with decomposition in the presence of a metal catalyst such as palladium.

If the alcohol moiety of the ester compound (XIII) is tertiary butyl alcohol or tetrahydropyranyl alcohol, the ester is treated with an arylsulfonic acid such as p-toluenesulfonic acid to yield an objective product.

This method is shown, for example, as follows.

CH30 C H2O OOH Even if a tertiary butyl ester is only fused by heating, it is decomposed to yield an objective free 3-indolyl aliphatic acid derivative (XI).

Sometimes a free 3-indolyl aliphatic acid compound may be obtained by treating an amide of the corresponding 3-indolyl aliphatic acid compound with a suitable amount of nitrous acid or its salt in an inert solvent.

The following compounds, for example, are prepared by this method.

The esters which are the starting materials used in this reaction are prepared in the following manners:

That is, 3-indolyl aliphatic acid esters represented by the general formula,

wherein R R R and n are as defined before and R is an alkoxy, tetrahydropyranyloxy or benzyloxy group, are reacted with an acyl compound represented by the general formula R COY (VI) wherein R and X are as defined before, whereby l-alicyclic compound-substituted 3-indolyl aliphatic acid esters represented by the general Formula XII wherein R R R R and n are as defined before and R is as defined in the Formula XIII.

The above reaction is effected in the presence of an inert solvent such as, for example, benzene, toluene, xylene, dimethylformamide, ether, tetrahydrofuran or dioxane. Generally, the 3-indolyl aliphatic acid ester is treated with sodium amide, sodium hydride or Grignards reagent, and is then subjected to acylation. As the acylating agent, an acyl halide, acid anhydride or mixed acid anhydride is used. Generally, the reaction proceeds at room temperature. In case the progress of the reaction is slow, the reaction system may be heated to a suitable temperature.

According to this method, the following compounds are obtained:

Tertiary-butyl l- 2-hydrindenylformyl) -2-methyl-5 methoxy-3-indolylacetate Tertiary-butyl l-(cyclohexylformyl)-2-methyl-5- methoxy-3-indolylacetate Tertiary-butyl l- (cyclohexylacetyl) -2-methyl-5- methoxy-3-indolylacetate Tertiary-butyl 1-cyclopentylformyl-Z-methyl-S- methoxy-B-indolylacetate Benzyl l-(A -tetrahydrobenzoyl)-2-methyl-S-methoxy- 3-indolylacetate Benzyl 1-(a-cyclohexylpropionoyl)-2,4-dimethyl-3- indolylacetate Benzyl l-(a-cyclohexylpropionoyl)-2,6-dimethyl-3- indolylacetate.

Benzyl 1-(A -tetrahydro-m-methylbenzoyl)-2-methyl-5- methoxy-B-indolylacetate.

Tetrahydropyranyl l-(n -cyclopentylformyl)-2-methyl- 5-methoxy-3-indolylacetate.

Tetrahydropyranyl 1-(2-indenylformyl)-5-methyl-3- indolylacetate.

Tetrahydropyranyl 'y-{1-(3'-indenylacetyl)-2-methyl-5- chloro-3-indolyl}-butyrate.

Tetrahydropyranyl 'y-{1-hydrindenylformyl-2-methyl-5- methoxy-3-indolyl}-propionate.

Tertiary-butyl 'y-{1-hydrindenylformyl-2-methyl-5- methoxy-3-indolyl}-propionate.

Ethyl 1-(A -tetrahydrobenzoyl)-2-methyl-5-methoxy-3- indolyl-acetate.

Methyl 1-(2'-hydrindenylformyl)-2-n1ethyl-5-n1ethoxy-3- indolylacetate.

TABLE 1 Action Therapeutic EDEQ LD5Q l'tlLlO Compound (ing/kg.) (mg/kg.) LD /E D Phenylbutazone 230 720 3. 2 1-(2'-h vdrindenoyl) -2-meth yl- 130 1, 500 11. 5

5-methoxy-S-indolylacetic acid (present compound). l-(eyelohexylformyl)-2-methyl- 240 1, 500 0. 3

fi-methoxy-Z-indolylaectie acid (present compound).

f 50% inhibitory oral dose of edema induced in the rats hind paw aitcr in cction of earrageonin.

* 50% lethal dose for one week after oral administration to rats.

Phenylbutazone is a representative anti-inflammatory drug and one of the best drugs which are most widely used now, but its effect is rather low in spite of high acute toxicity.

On the other hand, these compounds shown in the above table did not develop toxic symptoms in rates even after oral administration of more than 1,000 mg./kg. dose and its toxicity was minimum low. In these cases, occult bleeding in their feces was negative. But, the effects of the present compounds are considerably high in comparison with phenylbutazone, oxyphenbutazone and the like. Therefore, therapeutic ratios of these compounds are far greater than those of the first class nonsteroidal anti-inflammatory drugs. It goes without saying that these compounds are extremely great valuable in practical field.

21 EXAMPLE 1 To a solution of25 g. of acetaldehyde p-methoxyphenylhydrazone in 250 ml. of dry ether was added 13.2 g. of dry pyridine. The mixture was maintained at '2-1 C. while 24.5 g. of cyclohexanecarboxylic chloride was added dropwise. After an addition, stirring was continued for additional 3 hours. The resultant precipitate was collected by filtration, dissolved with water and extracted with ether. The ether layer was combined with. the'filtrate, and the mixture solution was washed with Water and dried over anhydrous sodium sulfate. Thereafter, anhydrous sodium sulfate was removed by filtration. To the ether layer was added petroleum ether/and the resultant precipitate was collected by filtration, and then washed with petroleum ether and dried to give 12 g. of yellow crystals of acetaldehyde N -(cyclohexylformyl)-N p methoxyphenylhydrazone. The melting point was 1082111 C;

EXAMPLE 2 Yellow crystals of acetaldehyde N -(2-hydrindeny lformyl)-N -phenylhydrazone were prepared from acetaldehyde phenylhydrazone by a similar method to Example 2. The melting point was ll120 C. i

' EXAMPLE 4 Yellow "crystals of benzaldehyde N -(2-hydrindenylformyl)-N -phenylhydrazine were prepared from acetaldehyde phenylhydrazoneby a similar method to Example 2. The melting point was l35140 C.

EXAMPLE 5- Yellow crystals of acetaldehyde "N -2-hydrindenylacetyl-N -phenylhydrazonewere prepared from acetaldehyde phenylhydrazone by a similar method of Example 2. The melting point was 125 128" C.

EXAMPLE 6 Colorless crystals of acetaldehyde N -(3'-methyl-1'- cyclohexylformyl) -N p-methoxyphenyl hydrazone were prepared from acetaldehyde p-methoxyphenylhydrazone by a similar method of Example 2. Themelting point was 106 -'-109 C.

EXAMPLE 7 Yellow crystals of acetaldehyde N -(2-indenylpropionyl)-N -(p-chlo'roph,enyl)hydrazone were prepared from acetaldehyde p-chlorophenylhydrazone' by a similar method to Example 2'. The melting point was 125 130 C.

. EXAMPLE '8 Colorless crystals of acetaldehyde N -(cyclohexylacetyl)-N -(p-methylthiophenyl)hydrazone were prepared from acetldehyde p-methylthiophenylhydrazone by a similar method to Example 2.

EXAMPLE 9 Colorless crystals of acetaldehyde N -(cyclohexylformyl)-N -(p-methylphenyl)hydrazone were prepared from acetaldehyde p-methylphenylhydrazone by a similar method to Example 2.

22 EXAMPLE 10 Into a, suspension of 6 g. of acetaldehyde N -(cyclohexylformyl)-N -(p-methoxyphenyl)hydrazone in 15 ml. of dry ethanol was slowly introduced gaseous hydrogen chloride at ice-salt temperatures. Crystals was dissolved and color of the solution changed to blue. After saturation of gaseous hydrogen chloride was removed under reduced pressure and a large amount of ether was added to the mixture. The resultant crystals were collected by filtration, washed with water, and dried to give 4.2 g. of colorless needles of N -(cyclohexylformyl) -N (p-methoxyphenyl)- hydrazine hydrochloride. The melting point was 184 C. (decomposition).

EXAMPLE 11 Colorless needles of N -(cyclopentylformyl)-N -(pmethoxyphenyl)-hydrazine hydrochloride were prepared from acetaldehyde N -(cyclopentylformyl)-N -(p-methoxyphenyl)-hydrazone by the same method with Example 10. The melting point was 177 C. (decomposition).

EXAMPLE 12 Yellow crystals of N -(2'-hydrindenylformyl)-N -(phenyl)hydrazine hydrochloride were prepared from acetaldehyde N (2'-hydrindenylformyl -N (phenyl hydrazone by the same method with Example 10. The melting point was 161 C. (decomposition).

EXAMPLE 13 A mixture of 3 g. of N -(2'-hydrindenylformyl)-N -(pmethoxyphenyl)hydrazine hydrochloride, 6 g. of levulinic acid, and 5 ml. of glacial acetic acid were stirred under heating at C. for 2 hours. After cooling, the reaction mixture was poured into cold water, and the resultant precipitate was collected by filtration and washed with water. Recrystallization from a mixture of acetone and water gave 1.5 g. of 1-(2'-hydrindenylformyl)-2-methyl-5- methoxy-3-indolylacetic acid, having the melting point of 168.5-169 C.

Analysis.Calculated for C H O N (percent): C, 72:71; H, 5.83; N, 3.85. Found (percent): C, 73.02; H, 5.77; N, 3.77.

EXAMPLE 14 A mixture of 3 g. of N -(2-hydrindenylformyl)-N -(pmethoxyphenyl)hydrazine hydrochloride, 1.4 g. of 5- acetyl-n-pentanoic acid and 5 ml. of glacial acetic acid was heated at 85 C. for 3.5 hours with stirring. After cooling, the mixture was poured into cold water, and the resultant black oily substance was precipitated. The precipitate was removed by filtration and was washed with water throughly. Recrystallization twice from a mixture of methanol and water gave colorless crystals of 1.5 g. of 'y {l (2 hydrindenylformyl) 2 methyl-5-methoxy-3- indolyl}butyric acid, having the melting point of 132.5"- 133.5 C.

Analysis. Calculated for C H O N (percent): C, 73.64; H, 6.44; N, 3.58. Found (percent): C, 73.87; H, 6.31; N, 3.72.

EXAMPLE 15 A mixture of 2 g. of N -(cyclohexylformyl)-N -(pmethoxyphenyl)hydrazine hydrochloride, 4 g. of levulinic acid and 1 ml. of glacial acetic acid was heated at 7580 C. for 2 hours with stirring. After cooling, the reactant was poured into cold water, and the resultant precipitate was collected by filtration, and washed with water. Recrystallization from a mixture of acetone and water gave colorless needles of 1.0 g. of 1-cyclohexylformyl-2-methyl-5- methoxyl-3-indolylacetic acid, having the melting point of 143.5-144.5 C.

Analysis.Calculated for C H O N (percent): C, 69.28; H, 7.04; N, 4.25. Found (percent): C, 69.39; H, 7.11; N, 4.14.

23 EXAMPLE 16 A mixture of 4 g. of benzaldehyde N -(2'-hydrindenyl formyl)-N -(p-methoxyphenyl)hydrazone and 15 ml. of levulinic acid containing gaseous hydrogen chloride was heated at 85 C. for 3 hours with stirring. After completion of the reaction, the reaction mixture poured into cold water, and the resultant crystalline solid was collected by filtration, washed with water. Recrystallization twice for a mixture of acetone and water gave yellow 1- (2' hydrindenylformyl) 2 methyl 5 methoxy 3- indolylacetic acid. The melting point was 167-169 C.

Analysis.Calculated for C H O N (percent): C, 72.71; H, 5.83; N, 3.85. Found (percent): C, 72.56; H, 6.23; N, 3.44.

EXAMPLE 17 Crystals of 1 (2 hydrindenylformyl 2 methyl 5- methoxy-3-indolylacetic acid were prepared from acetaldehyde N -(2 hydrindenylformyl)-N -(p-methoxyphenyl)hydrazone by the same method with Example 16. The melting point was 167-168.5 C. The infrared absorption spectra of this product was identical with that of crystals of 1 (2 hydrindenylformyl) 2 methyl 5- methoxy-B-indolylacetic acid obtained in Example 16.

EXAMPLE 18 To a liquid ammonia was added 0.5 g. of metallic sodium, when the mixture changed to nearly white color, 40 ml. of cold toluene was added thereto and allowed to stand at room temperature overnight. Thereafter, to a suspension of muddy soda amide in toluene was added 4.9 g. of ethyl 2-methyl-5-methoxy-3-indolylacetate and the mixture was stirred under a nitrogen gas stream. A mixture of 3 g. of cyclohexylformyl chloride and ml. of dry toluene was added dropwise to the mixture, which was stirred at room temperature for 3 hours and then was heated at 50 C. for 2 hours. The resultant precipitate was removed by filtration, and the filtrate was concentrated under reduced pressure to oily residue, which was purified by silica gel chromatography to give oily yellow material of ethyl 1-cyclohexylformyl-2-methyl-5-metl1oxy- 3-indolylacetate.

Analysis.Calculated (percent): N, 3.92. Found (percent): N, 3.53.

EXAMPLE 19 Crude tertiary-butyl 1-(2'-hydrindenylformyl)-2-methyl-5-methoxy-3-indolylacetate was obtained as an oily material from tertiary-butyl 2-methyl-5-methoxy-3-indolylacetate by the same method with Example 18. This crude product was used in Example 20 without purification.

EXAMPLE 20 A mixture of 5.0 g. of tertiary-butyl 1-(2-hydrindenylformyl)-2-methyl-5-methoxy-3-indolylacetate, 40 ml. of benzene and p-toluene sulfonic acid was refluxed. After completion of the reaction, the reaction mixture was allowed to stand at room temperature. After cooling, the mixture was washed with water thoroughly, and then was dried over anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure. The resultant solid was purified with acetone and acetone-water, and gave crystals of 1-(2'-hydrindenylformyl)-2-methyl- 5-methoxy-3-indolylacetic acid having the melting point of 166-168 C.

A suspension of 3.0 g. of 1-(2'-hydrindenylformyl)-2- methyl-5-methoxy-3-indolylacetic acid in 20 ml. of water was maintained pH 7.0-7.5 while 0.6 g. of sodium hydrocarbonate was added slowly to the mixture. After addition, the mixture was warmed for a few minutes, and the insoluble substance was removed by filtration. The filtrate was concentrated under reduced pressure, to an oily residue, which was extracted with chloroform. The chloroform solution was concentrated to a half of volume and allowed to stand in a refrigerator overnight.

The resultant crystals were collected by filtration to give the sodium salt.

EXAMPLE 21 To the mixture of 1 ml. of glacial acetic acid and 1.5 g. of fi-acetylpentanoic acid was added 2 g. of N -(cyclohexylformyl) N (p methoxyphenyl)hydrazine hydrochloride, and the mixture was heated at C. for 2 hours with stirring. The reaction mixture was poured into cold water to give dark brown oily material, which was solidified by cooling. The crystalline solid was removed by filtration, washed with water, and recrystallized from a mixture of ether and petroleum ether to yield 1 g. of white needles of ry-(1-cyclohexylformyl-2-methyl-5-methoxy-3-indolyl)butyric acid. The melting point was 7 8- 79 C.

Analysis.-Calculated for C H O N (percent): C, 70.56; H, 7.61; N, 3.92. Found (percent): C, 70.28; H, 7.83; N, 4.24.

What we claim is:

1. A 1-acyl-3-indolyl aliphatic acid derivative of the wherein R is a C -C cycloalkyl, 2-indenyl or 2'-hydrindenyl; R is hydrogen or methyl; R is hydroxy, lower alkoxy, benzyloxy, tetrahydropyranyloxy or amino; R is methoxy, ethoxy, methyl, ethyl, methylthio or ethylthio or a halo genor hydrogen atom; and n is 0 or an integer of 1 to 3.

2. A compound according to claim 1 wherein R is methyl; R is hydroxy, lower alkoxy or benzyloxy; R is methoxy, methyl, chlorine or hydrogen; and n is 0.

3. A compound according to claim 1 wherein R is methyl; R is hydroxy or lower alkoxy; R is methoxy or chlorine; and n is 0.

4. A compound according to claim 1 wherein R is methyl; R is hydroxy or lower alkoxy; R is methoxy or chlorine; and n is 1 or 2.

5. A l-acyl-3-indolylacetic acid of the formula,

HaCO- CHzCOOII -Clla C 0 l.

wherein R is a C -C cycloalkyl, 2-indenyl or 2'-hydrindenyl group.

6. 1 cyclopropylformyl 2 methyl 5 methoxy 3- indolylacetic acid.

7. 1 cyclohexylformyl 2 methyl 5 methoxy 3- indolylacetic acid.

8. 1 (2' idenylformyl) 2 methyl 5 methoxy- 3-indolylacetic acid.

9. 1 (2 hydrindenylformyl) 2 methyl 5 methoxy-3-indolylacetic acid.

References Cited UNITED STATES PATENTS 3,271,394 9/1966 Shen 260247.2

ALEX MAZEL, Primary Examiner J. A. NARCAVAG'E, Assistant Examiner U.S. Cl. X.R. 

